The Border Gateway Protocol (BGP) is a standardized exterior gateway protocol designed to exchange routing and reachability information among autonomous systems (ASs) on the Internet. BGP-labeled-unicast (BGP-LU) may be used as an inter-AS routing protocol, and may advertise a Multiprotocol Label Switching (MPLS) transport path between interior gateway protocol (IGP) regions and autonomous systems. BGP-LU may be used for traffic-engineering purposes in relation to autonomous systems.